PERC 2013 Abstract Detail Page

Quantum mechanics is challenging even for advanced undergraduate and graduate students. In the Schrodinger representation, the wave function evolves in time according to the time-dependent Schrodinger equation. The time-dependence of the wave function gives rise to time-dependence of the expectation value of observables. We explore the difficulties that advanced undergraduate and graduate students have with time-dependence of expectation values in quantum mechanics. We administered free response and multiple-choice questions to students to investigate the difficulties. We also interviewed some students individually using a think aloud protocol to obtain a better understanding of the rationale behind their responses. We find that many students struggle with time-dependence of expectation values of observables that do not have explicit time-dependence. We will discuss our findings. Supported by the National Science Foundation